Collapsible sterilization container

ABSTRACT

A collapsible single-use sterilization container for use in the sterilization of medical instruments is provided. The sterilization container includes a lid having central portion defined by a frangible region. Upon activation of the frangible region, the central portion may be removed rendering the sterilization container inoperable for future use.

The present application is a Divisional of U.S. patent application Ser.No. 12/317,658 filed on Dec. 24, 2008 now U.S. Pat. No. 8,241,587, inthe names of Steven Scott Friderich, Denise E. O'Connor, and Joseph A.Cesa, and claims priority thereto.

BACKGROUND

Sterilization of items used in medical procedures is vital to minimizingthe spread of harmful and infectious agents to patients. Typically, theitems used in medical procedures are placed into a sterilizationcontainer such as sterilization wrap made of a gas permeable material ora reusable vented rigid containers. These sterilization containerspreserve sterility of the items contained therein, as well as theinterior portion of these containers, after the containers and contentsof the container have been channeled through a sterilization procedure.During a typical sterilization procedure, the sterilization wraps orvented rigid containers are placed into a sterilization chamber, and thegas permeable material in the sterilization wrap or vents within therigid container allow a gas sterilant to contact the item to besterilized in the sterilization container.

Examples of current gas sterilization procedures include, gas plasmasterilization, steam sterilization, ethylene oxide sterilization,hydrogen peroxide sterilization, and ozone sterilization. Othersterilization procedures, such as irradiation have also been used.

Although utilization of sterilization wrap and/or use of vented rigidre-usable containers are generally effective, there are certain economicand protection disadvantages associated with use of these types ofsterilization containers.

For example, with regard to the use of sterilization wraps, the wrapsare made of a relatively thin, inexpensive, flexible material. Incertain circumstances, prior to wrapping the items with sterilizationwrap, the items to be sterilized are placed within a metal sterilizationtray having pointed edges. Sometimes, very small tears may develop inthe wrap if the wrap snags when it comes into contact with the pointededge. This may allow bacteria or other harmful substances to contaminatethe items therein after the sterilization container is complete.Further, this results in added expense because the items to besterilized will need to re-handled and re-sterilized at an additionalcost.

An additional issue with the use of sterilization wraps is a lack ofvisibility. Because sterilization wraps generally are not made oftransparent material, the medical professional utilizing it cannotvisually inspect the items contained therein for content or forassurance that the sterilization procedure has been completed. This canlead to a medical professional opening the wrong sterilization trayduring a procedure and/or lead to lack of confidence that the tray istruly sterilized. As a result, trays and articles may requireunnecessary rehandling and resterilization which wastes both economicand time resources.

With regard to reusable vented rigid containers, although generallyeffective, these containers must be thoroughly maintained and cleanedbetween uses so that they may be re-used. In contrast, sterilizationwrap may be discarded after a single use. This re-use of thesterilization container drains an exorbitant amount of hospital economicand time resources because staffing levels often need to be increased inorder to maintain these rigid containers. Additionally, the longer thecontainers are in use, the less confidence clinicians have in thesterilization efficacy of the containers. Ultimately, these containersmust be repaired, reconditioned, or discarded.

Thus, there remains a need in the art for sterilization containers thatare economical, provide ease of visual inspection, and that impartconfidence in sterility among clinicians.

SUMMARY

The present invention provides for single use substantially transparentrigid sterilization containers. The sterilization container includes atray having a plurality of sides, a base and a rim. The tray may beformed of a substantially transparent material adapted to withstandexposure to steam and ethylene oxide sterilization without degradationof the tray. The plurality of sides of the tray may also include aliving hinge. That is, the plurality of sides of the tray may form aseam or seams located at an intersection of adjacent sides of the tray.An additional seam or seams may be fully contained within one side ofthe tray. Advantageously, the living hinge allows the sides of the traysto be folded down on top of the base to create a low volume storageprofile. The sterilization container also includes a lid having a topside, a bottom side, a peripheral portion, and a central portion. Theperipheral portion of the lid, which is adapted to fixedly engage therim of the tray, includes a locking mechanism that engages the rim. Thecentral portion of the lid includes at least one opening therein. Thecentral portion is further defined by a frangible region comprising aplurality of frangible elements and includes a means for removal of thecentral portion by activation of the frangible region. The sterilizationcontainer also includes a gas permeable filter positioned incommunication with a side of the lid.

Desirably, the container may be made of a plastic. This allows thecontents of the container to be at least partially visible aftersterilization of the container and prior to removal of the lid.Additionally, desirably the filter of the container is in communicationwith the bottom side of the lid but may be in communication with the topside of the lid and may cover the at least one opening in the centralportion. Having the filter in communication with the at least oneopening allows the sterilant to pass through the filter during thesterilization process in order to contact the items to be sterilized.The filter may be a spunbond, meltblown, spunbond laminate (SMS) but mayinclude may be many other materials which would allow sterilant to passthrough it during the sterilization process.

Additionally, the tray may be made of four sides and the central portionof the lid may include frangible elements such scores, perforations,embossments, seams, or combinations thereof. These frangible elementsmay be activated by applying pressure on the frangible elements andremoving the central portion with a hook, handle, tab, or the like.

The locking mechanism may include a cantilevered projection. The lockingmechanism may also include sealing polymer engaged with the peripheralportion of the lid. In use, this sealing polymer will melt during thesterilization process and will harden after the process is over. Thisreinforces and strengthens the seal between the peripheral portion ofthe lid and tray. The sealing polymer is desirably a polyolefin anddesirably has a melting point less than the temperature required forsterilization, desirably less than 134 degrees centigrade.

Another aspect of the invention addresses a single-use container for usein sterilization of medical instrument. The sterilization containerincludes a top and a bottom composed of a rigid material. The containeralso includes a plurality of sides made from a non-rigid material andthat are attached to the top and the bottom. Desirably, at least one ofthe four sides includes a peripheral portion defined by a frangibleregion having a plurality of frangible elements. The peripheral portionmay further include a means for removal of the peripheral portion byactivation of the frangible region.

Another aspect of the invention addresses methods for sterilizing itemsfor use in a medical procedure. This method includes providing asterilization container having a tray having a plurality of sides, abase and a rim. The tray may be formed of a substantially transparentmaterial adapted to withstand exposure to steam and ethylene oxidesterilization without degradation of the tray. The sterilizationcontainer also includes a lid having a top side, a bottom side, aperipheral portion, and a central portion. The peripheral portion of thelid, which is adapted to fixedly engage the rim of the tray, includes alocking mechanism that engages the rim. The central portion of the lidincludes at least one opening therein. The central portion is furtherdefined by a frangible region comprising a plurality of frangibleelements and includes a means for removal of the central portion byactivation of the frangible region. The sterilization container alsoincludes a gas permeable filter positioned in communication with a sideof the lid. The method also includes placing medical instruments insidethe sterilization container; inserting the sterilization container intoa sterilization chamber for a length of time sufficient to sterilize themedical instruments; and removing the sterilization container from saidsterilization chamber. The method may further include the step ofproviding instructions regarding accessing the sterilized items byremoving the central portion with the means for removal of the centralportion by activation of the frangible region.

Yet another aspect of the invention addresses methods for sterilizingitems for use in a medical procedure. This method includes providing asterilization container having a top and bottom composed of a rigidmaterial. The container also includes a plurality of sides, composed ofa non-rigid material, and attached to the top and the bottom. At leastone of the four sides includes a peripheral portion by a frangibleregion which includes a plurality of frangible elements. Desirably, theperipheral portion further includes a means for removal of theperipheral portion by activation of the frangible region. The methodalso includes placing medical instruments inside the sterilizationcontainer; inserting the sterilization container into a sterilizationchamber for a length of time sufficient to sterilize the medicalinstruments; and removing the sterilization container from thesterilization chamber.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a single use sterilization containerwhich includes a rigid top and bottom and non-rigid sides.

FIG. 2 is a perspective view of a single use sterilization containerwhich includes a filter in communication with the central portion of thelid.

FIG. 3 is a perspective view of locking mechanisms for the single usesterilization container which includes a filter in communication withthe central portion of the lid

DETAILED DESCRIPTION

The apparatus of the present invention provides for non-reusable rigidsterilization containers for use in medical instrument sterilizationprocedures. These sterilization containers provide for ease of visualinspection and impart an increased confidence in sterility amongclinicians.

The invention will be described with reference to the followingdescription and figures which illustrate certain embodiments. It will beapparent to those skilled in the art that these embodiments do notrepresent the full scope of the invention which is broadly applicable inthe form of variations and equivalents as may be embraced by the claimsappended hereto. Furthermore, features described or illustrated as partof one embodiment may be used with another embodiment to yield still afurther embodiment. It is intended that the scope of the claims extendto all such variations and embodiments.

Turning to FIG. 2, a single use sterilization container is provided. Thesterilization container includes a tray 10. The tray may be made of arigid material that is substantially transparent. That is, the tray maybe made of a material that allows a viewer of the tray to visualize thecontents of the tray by utilizing normal human visual acuity withoutopening the tray. Further, the rigid material of tray should allow thetray to withstand the temperature required for sterilization of the traywithout degradation of the tray. That is, the tray should be able towithstand temperatures of from about 100 degrees centigrade to 300degrees centigrade without melting, bending, or losing strength.Suitable materials for use in the tray include, but are not limited to,various plastics including polyethylenes and polypropylenes.

The tray may be a variety of shapes and sizes including, but not limitedto, circular, oblong, trapezoidal, triangular, rectangular, and square.Additionally, the tray includes a base 30 a rim 40 and may comprises aplurality of sides 20. Advantageously, the tray may also include aliving hinge. That is, the plurality of sides of the tray may form aseam 50 or seams located at an intersection of adjacent sides of thetray. An additional seam or seams may be fully contained within one sideof the tray.

Regardless of the shape, size, or number of sides, the tray should beadapted to receive a lid 60 in communication with it. Like the tray, thelid may also be composed of a rigid material that may or may not betransparent, such as, for example, various plastics includingpolypropylene and polyethylene.

Regardless of the type of material that makes up the lid, the lid shouldinclude a top side 70, bottom side 80, central portion 100 andperipheral portion 90. In practice, medical instruments for use during asterilization procedure are placed inside the tray 10. Typical gassterilization procedures include, for example, gas plasma sterilization,steam sterilization, ethylene oxide sterilization, hydrogen peroxidesterilization, and ozone sterilization.

Once the instruments are placed with the tray, the lid is then snappedonto the tray prior to entering a sterilization chamber. Desirably thelid will include one or more locking mechanisms that allow theperipheral portion of the lid to fixedly engage the rim of the tray.That is, the peripheral portion locks together with the tray and cannotbe removed without sufficient force necessary to destroy either aportion of the locking mechanism, the rim, the lid, or combinationsthereof so that the tray cannot be easily reconditioned repaired orreused.

Turning to FIG. 3, suitable locking mechanisms include, but are notlimited to projections that extend from the peripheral portion of thelid and that fixedly engage the rim of the tray. These projectionsinclude, but are not limited to, cantilevered projections 110.Additional locking mechanisms may include the use of a sealing polymer180, such as, for example a sealing polymer made of a polyolfefin. Inpractice this sealing polymer will melt during the sterilization processand will harden after the process is over. This reinforces andstrengthens the seal between the peripheral portion of the lid and tray.Typical sterilization process temperatures range from 100 degreescentigrade to 300 degrees centrigrade.

Returning to FIG. 2, the central portion of the lid may also include atleast one opening 120 therein and filter 130 which is at least inpartial communication with the at least one opening, either on thebottom side or top side of the lid. The opening(s) and filter allow thesterilant to pass through the outside of the sterilization containerinto the inside of the sterilization container where the medicalinstruments may be contacted with the sterilant during the sterilizationprocess. Advantageously, upon removal of the central portion of the lid,the filter 130 may be unfolded outward to cover the non-sterile sidesand edges of the sterilization container. This allows the clinician tosafely and confidently remove the medical instruments from thesterilization container without compromising the sterility of theinstruments.

Virtually any gas permeable material may be used in conjunction with oras alternative to a filter provided that the material is permeable to asterilizing gas but impermeable to airborne microbes, bacteria, virusesand mixtures thereof. Suitable gas permeable materials useable in thepresent invention include, for example, medical grade paper, nonwovenmaterials and other similar gas permeable materials. Generally, gaspermeable materials which may be used in the present invention arepermeable to water vapor and have a minimum water vapor transmissionrate (WVTR) of about 300 g/m²/24 hours, calculated in accordance withASTM Standard E96-80. Suitable medical grade paper includes, forexample, AMCOR PLP reinforced coated paper available from AMCOR,Limited.

Suitable nonwoven materials useable as the gas permeable material of thesterilization container of the present invention include, for example,airlaid nonwoven webs, spunbond nonwoven webs, meltblown nonwoven webs,bonded-carded-webs, hydroentangled nonwoven webs, spunlace webs and thelike. The method of manufacturing each of these materials is known inthe art. Laminates of these materials may also be used.

Of these nonwoven materials, the fibrous material web may comprise anonwoven meltblown web. Meltblown fibers are formed by extruding amolten thermoplastic material through a plurality of fine, usuallycircular, die capillaries as molten fibers into converging high velocitygas (e.g. air) streams that attenuate the fibers of molten thermoplasticmaterial to reduce their diameter, which may be to microfiber diameter.Thereafter, the meltblown fibers are carried by the high velocity gasstream and are deposited on a collecting surface to form a web ofrandomly disbursed meltblown fibers. Such a process is disclosed, forexample, in U.S. Pat. No. 3,849,241 to Butin, et al. Generally speaking,meltblown fibers may be microfibers that may be continuous ordiscontinuous, and are generally smaller than 10 microns in diameter,and are generally tacky when deposited onto a collecting surface.

The nonwoven material web may be a nonwoven spunbond web. Spunbondedfibers are small diameter substantially continuous fibers that areformed by extruding a molten thermoplastic material from a plurality offine, usually circular, capillaries of a spinnerette with the diameterof the extruded fibers then being rapidly reduced as by, for example,eductive drawing and/or other well-known spunbonding mechanisms. Theproduction of spun-bonded nonwoven webs is described and illustrated,for example, in U.S. Pat. No. 4,340,563 to Appel, et al., U.S. Pat. No.3,692,618 to Dorschner, et al., U.S. Pat. No. 3,802,817 to Matsuki etal., U.S. Pat. No. 3,338,992 to Kinney, U.S. Pat. No. 3,341,394 toKinney, U.S. Pat. No. 3,502,763 to Hartman, U.S. Pat. No. 3,502,538 toLevy, U.S. Pat. No. 3,542,615 to Dobo, et al., and U.S. Pat. No.5,382,400 to Pike, et al. Spunbond fibers are generally not tacky whenthey are deposited onto a collecting surface. Spunbond fibers cansometimes have diameters less than about 40 microns, and are oftenbetween about 5 to about 20 microns.

The nonwoven material web may also comprise a laminate material such asa spunbond/meltblown/spunbond, or SMS, material. A typical SMS materialis described in U.S. Pat. No. 4,041,203 to Brock et al. Other SMSproducts and processes are described, for example, in U.S. Pat. No.5,464,688 to Timmons et al.; U.S. Pat. No. 5,169,706 to Collier et al.;and U.S. Pat. No. 4,766,029 to Brock et al. Generally, an SMS materialwill consist of a meltblown web sandwiched between two exterior spunbondwebs. Such SMS laminates are available commercially from Kimberly-ClarkCorporation under marks such as KIMGUARD®. The spunbonded layers on theSMS laminates provide durability and the internal meltblown layerprovides porosity.

As discussed above, once the sterilization containers of the presentinvention containing the items to be sterilized are placed within thesterilization chamber, the sterilization chamber is closed and a gassterilant is introduced into the container. The amount of time the itemsin the compartment are subjected to the gas sterilant depends on variousfactors, including the type of gas sterilant used, the number of medicalinstruments placed in the sterilization container as well as otherfactors. Those skilled in the art will be able to determine theappropriate amount of time the gas sterilant should remain in thechamber based on these and other factors.

Once sterilized, the sterilization containers are removed from thechamber and the sterilization container with the sterilized itemscontained therein are stored or placed for use. After use, the medicalinstruments are cleaned and the sterilization containers may be stackedand disposed of or recycled.

Advantageously, the central portion of the lid is defined by a frangibleregion having a plurality of frangible elements 150. These frangibleelements may include, but are not limited to scores, perforations,embossments, seams or combinations thereof as known in the art. Thesefrangible elements create a weaker, less sturdy region within the lid ofthe container which is adapted to tear or rupture upon application ofsufficient force. That is, the frangible region should rupture with theuse of ordinary force applied to it by a medical or hospital worker.

Additionally, the central portion may include a means for removal 160 ofthe central portion. The means for removal may be a hook, handle, tab,body parts, or the like. The frangible region may be activated byapplying force or pressure to the frangible elements by use of the meansfor removal. That is, the frangible region should rupture with the useof ordinary force applied to it by a medical or hospital worker, i.e.one hand applying force to the means for removal. Advantageously theforce required for removal of the central portion is concentrated nearthe means for removal. This lowers the force required for removal. Afteractivation of the frangible region, the central portion of the lid ispermanently removed. Thus, after sterilization, and upon removal of thecentral portion from the lid, the central portion cannot be rejoinedwith the lid to create a closed sterilization container, and thesterilization container cannot be reused. This is a safety featuredesigned to prevent the accidental use of non-sterile medicalinstruments.

Of note, although the frangible region should be flexible enough toallow ease of removal of the central portion, it should be sturdy enoughfor sterilization containers to be stored, stacked, and/or handledwithout rupturing the frangible region. Additionally, the filter 130should overlap the frangible region so that bacteria or other harmfulmaterial does not pass through the frangible elements into the inside ofthe sterilization container after a sterilization procedure has beencompleted.

In addition to the sterilization container described above, the presentinvention encompasses a single-use container 10 for use in sterilizationof medical instrument. The sterilization container includes a lid or top20 and a bottom 30 composed of a rigid material that is substantiallytransparent. That is, the top and bottom may be made of a material thatallows a viewer of the top and bottom to visualize the contents locatedthere between by utilizing normal human visual acuity. Further, therigid material of the top and bottom should allow the top and bottom towithstand the temperature required for sterilization without degradationof the top and bottom. That is, the top and bottom should be able towithstand temperatures of from about 100 degrees centigrade to 300degrees centigrade without melting, bending, or losing strength.Suitable materials for use in the top and bottom include, but are notlimited to, various plastics including polyethylenes and polypropylenes.Further, the top and bottom may be a variety of shapes and sizesincluding, but not limited to, circular, oblong, trapezoidal,triangular, rectangular, and square.

The container also includes a plurality of sides 20 made from anon-rigid material and that are attached to the top and the bottom. Theplurality of sides may be attached to the top and bottom by any methodknown in the art, including, by way of non-limiting example an adhesive.As discussed above, the non-rigid material may include virtually any gaspermeable material such as, for example, a non-woven material.Advantageously, the use of a non-rigid material for the sides allows thesides of the container to be collapsed after use to create a low volumestorage profile.

Desirably, at least one of the plurality of sides includes a closableopening for insertion of a medical instruments tray 80 therethrough.Once the tray has been inserted, the side may be closed using any methodknown the art for closing an opening of a non-rigid material including,for example, applying an adhesive 170 or using a heat seal as known inthe art. Thereafter, the sterilization container may be used in asterilization process as described above.

Desirably, at least one of the four sides includes a peripheral portion50 defined by a frangible region having a plurality of frangibleelements. These frangible elements may include, but are not limited toscores, perforations, embossments, seams or combinations thereof asknown in the art. These frangible elements create a weaker, less sturdyregion within at least one side of the container which is adapted totear or rupture upon application of sufficient force. That is, thefrangible region should rupture with the use of ordinary force appliedto it by a medical or hospital worker.

The peripheral portion may further include a means for removal of theperipheral portion by activation of the frangible region 70. The meansfor removal may be a hook, handle, tab, body parts, or the like. Thefrangible region may be activated by applying force or pressure to thefrangible elements by use of the means for removal. That is, thefrangible region should rupture with the use of ordinary force appliedto it by a medical or hospital worker, i.e. one hand applying force tothe means for removal. Advantageously the force required for removal ofthe peripheral portion is concentrated near the means for removal. Thislowers the force required for removal. After activation of the frangibleregion, at least a portion of the peripheral portion is permanentlyremoved and the container can no longer be fully closed. Thus, aftersterilization, and upon removal of the peripheral portion from, a gap isleft within at least one side and the sterilization container cannot bereused. This is a safety feature designed to prevent the accidental useof non-sterile medical instruments.

In addition to the sterilization containers described above, the presentinvention encompasses a method for sterilizing items for use in amedical procedure. This method includes providing a sterilizationcontainer having a tray having a plurality of sides, a base and a rim.The tray may be formed of a substantially transparent material adaptedto withstand exposure to steam and ethylene oxide sterilization withoutdegradation of the tray. The sterilization container also includes a lidhaving a top side, a bottom side, a peripheral portion, and a centralportion. The peripheral portion of the lid, which is adapted to fixedlyengage the rim of the tray, includes a locking mechanism that engagesthe rim. The central portion of the lid includes at least one openingtherein. The central portion is further defined by a frangible regioncomprising a plurality of frangible elements and includes a means forremoval of the central portion by activation of the frangible region.The sterilization container also includes a gas permeable filterpositioned in communication with a side of the lid. The method alsoincludes placing medical instruments inside the sterilization container;inserting the sterilization container into a sterilization chamber for alength of time sufficient to sterilize the medical instruments; andremoving the sterilization container from said sterilization chamber.The method may further include the step of providing instructionsregarding accessing the sterilized items by removing the central portionwith the means for removal of the central portion by activation of thefrangible region.

In addition to the sterilization containers described above, the presentinvention encompasses yet another method for sterilizing items for usein a medical procedure. This method includes providing a sterilizationcontainer having a top and bottom composed of a rigid material. Thecontainer also includes a plurality of sides, composed of a non-rigidmaterial, and attached to the top and the bottom. At least one of thefour sides includes a peripheral portion by a frangible region whichincludes a plurality of frangible elements. Desirably, the peripheralportion further includes a means for removal of the peripheral portionby activation of the frangible region. The method also includes placingmedical instruments inside the sterilization container; inserting thesterilization container into a sterilization chamber for a length oftime sufficient to sterilize the medical instruments; and removing thesterilization container from the sterilization chamber.

We claim:
 1. A single-use container for use in sterilization of medicalinstruments, the container comprising: a top comprised of a rigidmaterial; a bottom comprised of a rigid material; a plurality of sidesattached to the top and the bottom and comprised of a non-rigid materialthat allows the sides of the container to be collapsed after use,wherein at least one of said sides is comprised of a gas permeablematerial, wherein at least one of the sides comprises a peripheralportion defined by a frangible region comprising a plurality offrangible elements, the peripheral portion further comprising a meansfor removal of the peripheral portion by activation of the frangibleregion.
 2. The container of claim 1 wherein the top and the bottomcomprise a plastic.
 3. The container of claim 1 wherein the plurality offrangible elements are scores, perforations, embossments, seams orcombinations thereof.
 4. The container of claim 1 wherein the means forremoval of the peripheral portion is a hook, handle or a tab.
 5. Thecontainer of claim 1, wherein each of the sides comprises a spunbond,meltblown, spunbond (SMS) laminate.
 6. The container of claim 1 whereinthe container has four sides and said four sides are attached to the topand the bottom.
 7. The container of claim 1 wherein at least one of theplurality of sides comprises a closable opening for insertion of amedical instruments tray therethrough.